The feed-in tariff for solar power generation has been halved David McHugh

David Cameron has been accused of hypocrisy for hosting a major green energy summit at the same time as slashing subsidies for solar power generation.

The third Clean Energy Ministerial conference, featuring more than 20 ministers from the world's leading and emerging economies, will take place in London later this month in what No 10 hopes will position the UK as a global leader in renewable power and build on the Prime Minister's claim to lead the "greenest government ever".

Yet The Independent on Sunday understands that one of the UK's largest solar energy companies has been invited to the conference not by the Government but by the US Department of Energy.

The conference will take place just weeks after the introduction of a new feed-in tariff for solar power generation in the UK, which campaigners warn will kill off the booming sector, with 5,000 job losses.

Last month, the Government lost a Supreme Court battle over its failure to consult on halving the subsidy for solar power from 43.3p to 21p per hour in December, allowing homeowners and businesses to carry on benefiting from the old rate until this month. But from 1 April, solar power carries the new 21p rate and further cuts to the subsidy are planned.

Howard Johns, spokesman for the Cut Don't Kill campaign, said: "The industry is already starting to stagnate, but this passing of the 21p mark is a brutal moment.

"People from the industry have stopped being invited to meetings with ministers. It seems highly hypocritical for David Cameron to host a summit on clean energy while presiding over this cut."

In an apparent snub to the British solar power industry, the Government has not invited anyone from the sector to the conference, which will take place at Lancaster House, London, on 25-26 April. Ed Davey, the Energy and Climate Change Secretary, will host the event alongside his US counterpart, Steven Chu.

But Solar Century, one of the largest UK solar firms, has been invited to attend by Mr Chu's department.

The meeting is the third annual Clean Energy Ministerial, with 23 nations taking part, including the US, China and India. The 23 nations account for 80 per cent of global greenhouse gas emissions and 90 per cent of investment in clean energy. The aim of the conference is to improve collaboration between nations on global projects, as well as driving "public-private engagement to support clean energy deployment".

Last year The IoS published an article about opposition to the subsidy cuts, with a coalition of 55 individuals and groups warning the Prime Minister will "strangle at birth" Britain's booming solar panel industry by halving the tariff overnight.

The High Court ruled it was unlawful to cut the subsidy without warning. Last month, the Supreme Court upheld the ruling, and anyone who generates electricity through solar panels was able to claim the higher subsidy to the end of March.

Ministers have blamed the popularity of the feed-in tariff on their decision to cut the rate, insisting that it was too expensive to sustain.

Downing Street and the Department for Energy and Climate Change declined to comment yesterday.